Printing machine



Nov. 22, 1938.

c. B. NELSON ET AL PRINTING MACHINE Filed Feb. 25, 1937 2 Sheets-Sheet 1NiOV. 22

c. B. NELSON ET AL PRINTING MACHINE 2 Sheet s 2 Filed Feb. 25, 1957Patented Nov. 22, 1938 UNITED STATES PATENT OFFICE PRINTING MACHINE NewYork Application February 23, 1937, Serial No. 127,102

4 Claims.

This invention relates to improvements in printing machines. In machinesof the multigraph form, the rotary drums are provided with longitudinalsurface slots into which are inserted, through an open end thereof, thetype or type bars or slugs having bodies shaped for interlockingengagement with the slots.

The use of cuts for illustrative purposes on conventional multigraphmachine drums alone or in conjunction with the conventional type ofslugs used in such machines has presented diiiiculties in that it hasbeen necessary to provide such cuts with ribbed formations correspondingto the type bodies which fit within the drum slots not only for thepurpose of securing the cuts in place on the drum but for affordingsupport for the printing surfaces of the cuts to prevent inward deflection of the printing surfaces during the printing operations. Thematerial of which the cuts are made of necessity is rather thin andrequires support at the transverse zones where the thin metal of whichthe cuts are formed bridges the drum slots.

One object of the present invention is to provide a segmental drum for amachine of the character mentioned having a smooth unslotted surface andwhich may be substituted for the conventional slotted drum and used witha printing plate having the copy, or matter to be reproduced includingillustrations if desired, etched or otherwise appropriately formedtherein, such improved drum having plate attaching means at thelongitudinal edges thereof. By the use of such improved drum and plate,the use of type or type bars is eliminated.

Another object of the invention is to provide plate attaching means atthe longitudinal edges of the drum, each of which attaching meanspreferably is adjustable for tightening the plate uniformly upon thedrum to prevent relative movement of the plate with reference to thedrum during the printing operation and thereby avoiding blurring orproducing non-uniform imprints. Since such printing plates arerelatively thin and for best results must be attached at several pointsalong each end thereof to retain the same in proper contact with thedrum and as the plates also contact with the rotary platen, or the like,during the printing operation, it is essential that the plate attachingmeans be so disposed and arranged as to avoid any possibility ofstriking and damaging the platen or other rolls or portions of themachine.

The present improved attaching and tightening means for securing theplates upon the drums (Cl. Mil-415.1)

preferably are disposed in all positions of adjustment inwardly of thecylindrical portion of the drum periphery so as to avoid striking ordamaging the platen roller even should the machine be operatedinadvertently without completely tightening the fastening means.

Another object of the invention is to provide plate attaching andtightening means comprising a plurality of studs or like members forengaging the ends of the plates within apertures provided therein andall of which members of each of the tightening means are simultaneouslyand uniformly adjustable by a common operating device.

Other objects of the invention relate to various features ofconstruction and arrangement of parts which will be apparent from aconsideration of the following specification and accompanying drawings,wherein:

Fig. l is a perspective view of an improved drum having a smoothunslotted surface and adapted for use on a conventional multigraphmachine;

Fig. 2 is an end view of the drum shown in Fig. l but showing a printingplate in conjunction therewith, the plate being shown in initiallyinstalled position;

Fig. 3 is a side elevation of a drum and plate embodying the presentimprovements;

Fig. 4 is a side elevation of an oscillatable rod and plate attachingstuds carried thereby which constitute a portion of the plate attachingmeans;

Fig. 5 is an enlarged broken perspective View of a portion of the shaftshown in Fig. 4;

Fig. 6 is an enlarged broken perspective View of a portion of one of theprinting plates showing the stud receiving aperture as being reenforcedat its periphery;

Fig. 7 is a plan View of an improved drum showing a plate in positionthereon;

Fig. 8 is a plan view of the drum partially broken away prior to theinstallation of the plate attaching means;

Fig. 9 is a sectional View taken on line 9-9 of Fig. 7 and showing inaddition portions of the rotary drum carrying reel or structure of aconventional multigraph machine; and

Fig. 10 is a broken sectional View illustrating a modification of theplate attaching means.

In the drawings, Ill indicates generally a segmental drum adapted to bemounted on the drum carrying rotary structure of a conventionalmultigraph machine, such structure being indicated fragmentally at H inFig. 7. The drum has a semi-cylindrical surface l2 upon which is adaptedto be secured a printing plate l3. The plate E3 preferably is relativelythin and has its outer surface etched or otherwise provided with thecopy to be reproduced including illustrations, if desired. The ends ofthe plate are provided with apertures I 4 for receiving the fasteningmeans later to be described.

As shown in Figs. 3 and 6, the apertures of the plate preferably areprovided with reenforcements I5 such as in the form of grommets, forexample, for preventing rupture of the plate during tightening of thelatter upon the drum by the attaching means.

The surface of the drum along the longitudinal edges Illa thereof isrelieved whereby such surface portions are disposed inwardly of thecylindrical portion of the drum and are provided with longitudinalpassages or bores for receiving rods or shafts I6, each of which carriesa plurality of plate engaging studs H, the intermediate studs in theform of the invention illustrated operating within transverse slots I8formed in said edge portions of the plate. It will be seen that theslots I8 permit the studs to be adjusted in directions to effect atightening or stretching of the plate upon the drum. The slots I8preferably terminate at ledges I9 which limit movement of the studs inone direction.

Secured to the shafts I6 are arms or levers which project inwardly ofthe drum as shown in Figs. 1 and 7 and are provided with apertures attheir inner ends for receiving bolts 2| pivotally mounted on pins 22carried in recesses in bosses 23 disposed between two of theintermediate reenforcing ribs 24. It will be seen that by adjusting thenuts 25, the levers or arms 20 can be swung in one direction or another,thereby adjusting the respective shafts I6 and swinging the studs I! tothereby effect tightening of the plate I3 upon the drum or to releasethe latter therefrom.

As shown in Fig. 7, a spring 26 may be disposed beneath each of the arms20 for swinging the same outwardly as the nuts are unscrewed from thebolts 2 I. As shown in Figs. 2 and '7, the outer ends of the studs I!are disposed inwardly of the cylindrical surface of the drum, or anextension of such surface, so that in any position of adjustment of thestuds, they will clear the platen (not shown) which presses the paperagainst the plate carried by the drum during the printing operation.

It is preferred that the printing plates I3 be preshaped toapproximately the contour shown in Fig. 2 prior to attachment of thesame to the drums. However, the plates are thin and quite flexible andmay be attached without such preshaping, if desired. When placed uponthe drum as shown in Fig. 2, the studs ll of each of the fasteningdevices are inserted in the corresponding openings I4 of the ends of theplates, after which, by use of a suitable wrench, the nuts are tighteneddown, thereby effecting movement of the studs in directions to draw theprinting plate into firm contact with the surface of the drum. Theprovision of two tightening devices is preferred for the reason thatless tension will have to be applied to the ends of the plates indrawing it into the desired firm contact with the drum than if only onesuch tightening device were employed. The likelihood of rupturing therelatively thin zinc plate at the apertures is thus reduced.

It will be noted in Fig. 7, which illustrates a printing plate I3 inprinting position on the improved drum, that the ends of the plate havebeen drawn inwardly of the cylindrical portion of the drum surface. Theplates, as stated, are thin and flexible and such inward deflection ofthe plates is due to the fact that the studs I! move in arcs about thecenters of the pins or shafts l6 and as the levers 20 are moved inwardlyby adjusting the nuts 25, the free edges of the plate I3 are likewisedrawn inwardly somewhat and thereby so positioned as to avoid anypossibility of striking the machine platen or other portion of themachine structure located close to the drum periphery.

In Fig. 10 of the drawings, the drum I B is similar to drum II] of theabove described modification and is provided with shafts I6 carryingstuds i! also similar to the corresponding elements above described. Inthis form of the invention, however, the shaft I8 is provided with aworm wheel 21 which is fixed thereto and which meshes with a worm 28carried by the key or wrench operable shaft 29. The shaft 29, as shown,is provided with a socket 30 for receiving a suitable key or wrench 3|for operating the same to effect adjustment of the studs I I intightening the printing plates (not shown in Fig. is) in proper positionon the drum.

The drums I9, I0 may be attached to the r0- tar-y structure Ii of themachine by any suitable means such as by the arms 32 which are providedwith screws 33 which when screwed inwardly are adapted to seat insockets provided in the axial shaft 34 of the rotary structure or headof the printing machine as illustrated in Fig. 7. The arms 32 arepivotally attached to pins 35 carried by adjacent reenforcing ribs 24.

Thus it will be seen that one who wishes to use an etched plate, forexample, in lieu of the conventional type or type bars may detach theconventional slotted drum from the machine and position one of theimproved drums thereon. The improved drum having an unslottedcylindrical or semi-cylindrical surface supports the printing platesthroughout the entire printing surface thereof which may be less than,or coextensive with such cylindrical surface. The relieved ends of thedrum periphery enable the studs to project through the same for engagingthe plates but yet to terminate inwardly of the orbit of the cylindricalportion of the drum so as to avoid damaging any portion of the machineregardless of the position of the studs. The tightening means disclosedare readily accessible and enable the user to secure the thin printingplates to the drum against relative movement during the printingoperation, thus insuring unblurred imprints. The etched or otherwiseformed printing surfaces of the plates I3 (which surfaces are notillustrated in the drawings) may be for either relief or intaglioprinting.

While we have disclosed a certain embodiment of our invention for thepurpose of illustration, we do not wish to be restricted specificallythereto except as limited by the appended claims.

1. In a printing machine, a segmental rotary drum having an intermediatesemi-cylindrical surface, longitudinal end portions disposed inwardlywith respect to said surface, said end portions each having alongitudinal recess therein and transverse slots communicating with saidrecess, an oscillatable shaft in each of said recesses, plate engagingstuds carried by said shaft and movable within said slots, said studshaving plate engaging ends projecting beyond the surface of therespective end portions but terminating inwardly of the cylindricalsurface of the drum, and means comprising swingable members accessiblefrom the interior of the drum for effecting the adjustment of saidshafts for swinging the studs thereof in directions for tightening theplate upon the cylindrical surface of the drum.

2. In a printing machine a segmentary drum having a semi-cylindricalplate supporting surface terminating at each longitudinal end ininwardly curved portions, said portions being longitudinally aperturedand transversely slotted, a rock shaft in each of said aperturesprovided with plate engaging studs extending through said slots beyondthe curved surface of the respective end portions but terminatinginwardly of the semicylindrical curvature of the drum, a lever attachedto each of said shafts, and threaded means within the drum engaging saidlevers for operating the same to effect movement of said studs indirections for tightening a plate upon the drum and swinging the engagedends of the plate inwardly of the drum periphery.

3. In a printing machine a segmentary drum having a longitudinallyapertured end portion provided with an exterior surface merging with butcurved inwardly from the surface of the drum, said end portion havingslots therein disposed transversely with respect to said longitudinalaperture, a rock shaft in said aperture, plate engaging studs carried bysaid shaft and each projecting through one of said slots beyond theadjacent surface of the respective end portion but terminating inwardlyof the curvature of the drum periphery, an operating lever secured tosaid shaft and projecting inwardly of the drum, and threaded meansengaging the end of said lever for operating the rod to swing said studsin a direction to tighten an apertured plate engaged thereby upon thesurface of the drum and to flex the engaged ends of the drum inwardly ofthe drum periphery.

4. In a printing machine a segmentary drum having a longitudinallyapertured end portion provided with an exterior surface merging with butcurved inwardly from the surface of the drum, said end portion havingslots therein disposed transversely with respect to said longitudinalaperture, a rock shaft in said aperture, plate engaging studs carried bysaid shaft and each projecting through one of said slots beyond theadjacent surface of the respective end portion but terminating inwardlyof the curvature of the drum periphery, an operating lever secured tosaid shaft and projecting inwardly of the drum, and threaded meanspivotally mounted within the drum and engaging the end of said lever foroperating the rod to swing said studs in a direction to tighten anapertured plate engaged thereby upon the surface of the drum and to flexthe engaged ends of the drum inwardly of the drum periphery.

CHRISTIAN B. NELSON. BER'I'IL LINDELL.

